Hammermill and feed control device therefor



April 1, 1-969 5 KOEHNEN ET AL 3,436,028

HAMMERMILL AND FEED CONTROL DEVICE THEREFOR Filed Nov. 25, 1966 Sheetof2 INVENTORS EARL AKOEHNEN OLA/:FNCE W MOBLEY, JR.

ATTORNEYS April 1, 1969 E. A. KOEHNEN ET AL 3,436,028

HAMMERMILL AND FEED CONTROL DEVICE THEREFOR Filed Nov. 25, 1966 7 Sheet2 of2 FIG. \3

INVENTORS. EA RL. A. KOE'HNEN CLAg ENCE W MOBLEY, JR.

AT TORNEYS United States Patent 3,436,028 HAMMERMILL AND FEED CONTROLDEVICE THEREFOR Earl A. Koehnen, Chaska, Minn., and Clarence W. Mo-

hley, Jr., Billings, Mont., assignors to Farmhand, Inc.,

South Hopkins, Minn., a corporation of Delaware Filed Nov. 25, 1966,Ser. No. 597,065 Int. Cl. B02c 13/06 U.S. Cl. 241186 Claims ABSTRACT OFTHE DISCLOSURE In the grinding of fibrous material, such as hay, in ahammermill, the hay is usually fed to the mill in slabs or cakes peeledfrom a hay bale. The slabs or cakes are delibered in succession to therotating hammers of the mill by the feeding rotor overlying and engagingeach slab as it moves in the downwardly sloping throat of the mill.Heretofore, when the trailing end of the slab or cake was moved beyondcontact with the feeding rotor, the loose trailing end or slug wouldgravitate into the path of the rotating hammers and be struck therebywith a heavy impact, imparting a shock load to the hammermill structureand effectively shortening the life of the components thereof, such asthe hammer elements, screen, shaft bearings and the like. Hence, theprimary object of this invention is the provision of a device forhammermills which will effectively support a slab or cake relative tothe rotating hammers in such manner that the slab is cut into by thehammers uniformly until the entire slab is ground, whereby to preventslugging.

Another object of this invention is the provision of an attachment ordevice as set forth, which provides a plurality of generally parallelguide channels for delivery of granular material to the grinding chamberof the hammermill.

Yet another object of this invention is the provision of a hammermillincluding a housing having an inlet for delivery of material to thegrinding chamber thereof, the throat having an inwardly and downwardlysloping bottom wall portion provided with a plurality of upstandingparallel guide plates for said material. The above, and still furtherhighly important objects and advantages of this invention will becomeapparent from the following detailed specification, appended claims andattached drawings. Referring to the drawings, which illustrate the invention, and in which like reference characters indicate like partsthroughout the several views:

FIG. 1 is a view in perspective of a hammermill incorporating the deviceof this invention;

FIG. 2 is an enlarged fragmentary transverse section, takensubstantially on the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary view in section, taken on the line 3-3 of FIG.2;

FIG. 4 is a fragmentary view partly in side elevation and partly insection, taken on the irregular line 44 of FIG. 3; and

FIG. 5 is a view in perspective of the feed control device of thisinvention.

A conventional hammermill is shown in the drawings ice as comprising ahousing 1 defining an inlet throat 2, a grinding chamber 3 and an outletopening 4, a rotary grinding head 5 journalled in the grinding chamber 3on a generally horizontal axis, a material feeding rotor 6 extendingtransversely of the throat 2 and journalled on an axis generallyparallel to the axis of rotation of the grinding head 5, asemi-cylindrical screen 7, and a discharge screw conveyor or auger 8.

The housing 1 comprises a pair of laterally spaced generally verticalside walls 9 and 10, a top wall 11, a bottom wall comprising a pair ofcooperating bottom wall sections 12 and 13, a rear wall 14 and a frontwall or skirt 15. A portion of the top wall 11, side walls 9 and 10, andbottom wall section 12, cooperate to define the inlet throat 2, and anopen-topped feeding tray 16 is riveted or otherwise rigidly secured tothe side walls 9 and 10 and bottom wall section 12 at the inlet end ofthe inlet throat 2. The bottom wall sections 12 and 13 slope downwardlyand rearwardly from the skirt 15, the bottom wall section 13 providing atrough portion 17 in which the auger 8 is disposed. The screen 7 is heldin place concentric to the grinding head 5 by a pair of flanges 18 andclamping brackets 19, one of each of which is shown in FIG. 2, and byinturned flanges 20 on an access door 21 that is hinged at its oppositesides to the sidewalls 9 and 10, as indicated at 22. The access door 21is releasably locked in closed position by a screw latch mechanism 23.

The grinding head 5 is of conventional design, involving a plurality ofaxially spaced generally rectangular plates 24, one of which is shown,keyed or otherwise rigidly secured to a central shaft 25 and having aplurality of circumferentially spaced rods 26 extending in a directionaxially therethrough. A plurality of rectangular grinding hammers 27 arejournalled on the rods 26 between different ones of the plates 24 forswinging movements between inoperative depending positions shown by fulllines in FIG. 2, and operative radially outwardly projecting positionsshown by dotted lines in FIG. 2, the hammers 27 assuming their radiallyprojecting operative positions responsive to rotation of the grindinghead 5. The shaft 25 is journalled in bearings 28, one of which is shownin FIG. I, mounted on the side walls 9 and 10, and is driven by suitablemeans not shown. The auger 8 is pinned or otherwise rigidly mounted onan auger shaft 29 that is journalled in bearings 30, one of which isshown in FIG. 1 secured to the sidewall 9, the auger 8 delivering groundmaterial outwardly through the discharge opening 4. The auger shaft 29is rotated by suitable means, not shown.

The feeding rotor 6 comprises a pair of end flanges 31 anda 32 connectedby a drum 33 having circumferentially spaced radially outwardlyprojecting toothed ribs 34 that extend axially between the end flanges31 and 32. The rotor 6 is mounted on an axial shaft 35 that extendsaxially outwardly beyond the end flanges 31 and 32 and through a pair ofarcuate slots 36 in the housing sidewalls 9 and 10. Opposite endportions of the shaft 35 are journalled in bearings 37 secured to theouter ends of a pair of mounting arms 38 that are pivotally secured torespective ones of the housing sidewalls 9 and 10 by pivot pins or thelike 39. The arms 38 are connected by an inverted generally U-shapedframe 40 which straddles the upper portion of the housing 1 and whichincludes depending leg portion 41 each pivotally connected at its lowerend to the adjacent arm 38 by a nut equipped bolt or the like 41a.

The slots 36 and pivotal connections 39 of the arms 38 permit thefeeding rotor 6 to move upwardly and downwardly within the inlet throat2, whereby the feeding rotor 6 may ride upon, and control feedingmovement of, material to the grinding chamber 3. Such bodily movement ofthe rotor 6 is controlled in part by a pair of disks 42 that areeccentrically mounted on a transverse shaft 43 adjacent respective onesof the side walls 9 and 10, the shaft 43 being journalled in suitablebearings in the sidewalls 9 and 10. The shaft 43 extends axially througha pair of slots 44 in the legs 41 and terminates at one end in anangularly displaced handle 45 by means of which the shaft 43 and disks42 may be rotated. The disks 42 are provided with alignedcircumferentially spaced openings 46 for reception of a stop bar 47which rests upon the top wall 11 in one selected position of the disks42 to permit maximum upward and downward bodily movement of the feedingrotor 6. By inserting the stop bar 47 through a selected pair of alignedopenings 46 and through the slots 44, bodily upward and downwardmovement of the feeding rotor 6 may be limited as desired. Further, thelegs 41 are provided with aligned openings 48 which, when the stop bar47 is inserted therethrough and through a given pair of aligned openings46, holds the rotor 6 against upward and downward movement in the inletthroat 2. Further, downward movement of the feeding rotor 6 is limitedby engagement of the disks 42 with a pair of rollers 49 journalled inthe upper end portions of the legs 41.

Feeding rotation is imparted to the feeding rotor 6 from a shaft 50journalled in suitable bearings in the side walls 9 and 10 and connectedto a source of power, not shown, through speed reduction gearingincluding a drive chain 51 entrained over a sprocket Wheel 52 fast onthe shaft 50 and a second sprocket whel 53 journalled on the pin orshaft 39 projecting laterally outwardly from the adjacent side wall 9. Asecond endless chain 54 is entrained over a sprocket wheel 55 journalledon the adjacent pin or shaft 39 for common rotation with the sprocketwheel 53, and another sprocket wheel 56 mounted fast on the adjacent endof the feeding rotor shaft 35, see particularly FIGS. 1 and 3. Asupporting bracket 57 rigidly secured to the adjacent wall 9 of thehousing 1, supports the outer end portion of the adjacent shaft or pin39.

The feed control device of this invention comprises a generallyrectangular base plate 58 bent intermediate its inner and outer ends 59and 60 respectively to form inner and outer plate portions 61 and 62respectively, and a plurality of laterally spaced parallel rigid guideplates 63 projecting upwardly from the base plate portion 61. As shownin FIGS. 1, 2 and 5, the guide plates 63 eX- tend from the inner end 59toward the outer end 60, portions of the guide plates 63 overlying apart of the outer base plate portion 62. A pair of mounting brackets 64are provided with slots 65 for the reception of nut-equipped mountingscrews 66 that extend through suitable apertures in the side walls 9 and10 within the throat 6. Further, the base plate portion 62, adjacent theouter end 60 thereof, is provided with a slot 67 for reception of anut-equipped screw 68 that extends through a suitable opening in thebottom wall portion 12 at the outer end portion of the throat 2.

In the normal use of a hammermill of the type illustrated for choppingor grinding baled hay, without the use of the device of this invention,a slab or cake of baled hay, indicated at X in FIGS. 2 and 3, is moveddownwardly and inwardly on the infeed portion 12a of the bottom wallsection 12, and is delivered to the path of circular travel of thehammer elements 27 by the feeding rotor 6. With the bale slab X disposedon the portion 12a, the slab is directed generally toward the bottomportion of the grinding head, and becomes disengaged from the feedingrotor 6 while yet of fairly large size. When thus disengaged from thefeeding rotor 6, this remaining portion or slug falls or is drawn intothe path of the hammers 27 by the hammers themselves, the hammers 27striking the slug with a heavy impact which not only interferes witheflicient grinding of the slug material, but also places the entirehammermill under a severe shock 4 load. Moreover, the impact of the slugagainst the screen 7 is apt to deform or otherwise injure the screen 7,necessitating frequent replacement thereof.

With the feed control device of this invention installed in the infeedthroat 2, as shown in FIGS. 1-3, the base plate 58 rests upon the bottomwall portion 12a, the guide plates 63 underlying the feeding rotor 6,the top edges of the guide plates 63 being disposed in a plane whichintersects the rotary grinding head 5 upwardly of the bottom portionthereof. Thus, when the slab X of hay is fed into the inlet throat 2,and moved toward the grinding head 5 by the feeding rotor 6, the slab Xrides on the top edges of the guide plates 63, and is disposedsubstantially on a level with the axis of the grinding head 5. As thegrinding head 5, and hammer elements 27 carried thereby, rotate in acounterclockwise direction with respect to FIG. 2, as indicated by thearrow therein, the hammer elements 27 engage the leading end of the slabX in a direction which tends to compress the leading end portion of theslab X directly toward the underlying guide plates 63, without tendingto pull the slab of hay into the grinding chamber. Further, in view ofthe fact that the slab X is carried at a higher level than normally, thetooth-equipped ribs 34 of the feeding rotor 6 are disposed in engagementwith the slab until a much smaller unsupported slug remains at thetrailing end of the slab than heretofore. The inner ends of the guideplates 63 support the remaining slug as it is chopped away by therotating hammer elements 27 until the slug is substantiallydisintegrated, or cut down to such small size as to be ineffective tohinder the smooth operation of the hammermill.

An added advantage of the feed control device above described lies inits use as a guide for grain and the like to the interior of the chamber3. The guide plates 63 cooperate with the base plate 58 to defineupwardly opening parallel channels which guide the grain for uniformfeeding over the entire width of the inlet throat 2, so thatsubstantially the entire axial length of the grinding head 5 is utilizedin grinding the material. This is particularly important when thehammermill is mounted on a portable vehicle, when the vehicle is in suchposition that the axis of the grinding head shaft 25 is tilted.

While the feed control device of this invention has been shown anddescribed as an attachment for existing hammermills, it will beappreciated that the same may be substituted for the bottom wallportions 12a of the hammermill in the manufacture thereof. Further,While we have shown and described a commercial embodiment of our feedcontrol device for hammermills, it will be understood that the same iscapable of modification without departure from the spirit and scope ofthe invention, as defined in the claims.

What is claimed is:

1. A feed control device for hammermills including, a housing definingan inlet throat and an outlet, a rotary head journalled in said housingon a generally horizontal axis extending in a direction transversely ofsaid throat, a plurality of hammer elements carried by said rotary head,a feeding rotor journalled in said throat on an axis generally parallelto said head, and means for imparting rotation to said rotary head andfeeding rotors, said device comprising:

(a) a base plate having opposite inlet and delivery ends,

(b) means for mounting said base plate in said throat in underlyingspaced relation to said feeding rotor with said delivery end directedtoward a circle defined by said hammer elements,

(0) and a plurality of laterally relatively widely spaced parallelrelatively narrow guide elements projecting upwardly from said baseplate and extending in a direction normal to said inlet and deliveryends of said base plate, said guide elements having parallel uppermaterial supporting edges in a common plane for supporting and directingfibrous material generally radially toward said rotary head, said guideelements cooperating with said base plate to define a plurality of feedchannels extending toward said rotary head below said upper edges fordirecting granular material to the rotary head at a level substantiallybelow the axis of the rotary head when said device is mounted in saidinlet throat.

2. The feed control device defined in claim 1 in which said guideelements comprise rigid guide plates having lower edges anchored to saidbase plate. v

3. The feed control device defined in claim 1 in which said base plateis bent to provide angularly spaced inlet and delivery end portions,said guide elements projecting upwardly from said delivery end portion.I

4. A hammermill comprising:

(a) a housing defining a grinding chamber and an inlet throat and anoutlet communicating with said chamber,

(b) a rotary head journalled in said chamber on a generally horizontalaxis extending in a direction transversely of said throat and having aplurality of hammer elements thereon,

(c) a feeding rotor journalled in said throat on an axis parallel to theaxis of said head,

(d) means for imparting rotary movement to said head and feeding rotor,

(e) a base plate underlying said feeding rotor and providing a bottomwall surface of said throat and having an inner end directed generallytoward said rotary head,

(f) and a plurality of relatively narrow guide elements secured to saidbase plate in underlying spaced relation to said feeding rotor, saidguide elements projecting upwardly from said base plate in laterallyrelatively widely spaced parallel relationship and extending from saidinner end of the base plate toward the opposite end thereof, said guideelements having parallel upper material supporting edges in a commonplane for supporting and directing fibrous material generally radiallytoward said rotary head, said guide elements cooperating with said baseplate to define a plurality of feed channels extending toward saidrotary head below said upper edges for directing granular material tothe rotary head at a level substantially below the axis of the rotaryhead.

5. The hammermill defined in claim 4 in which said guide elements arespaced apart a distance to support slabs of baled hay on said upperedges thereof in upwardly spaced relation to said base plate adjacentits inner ANDREW R. JUHASZ, Primary Examiner.

US. Cl. X.R.

